Grinding fixture for piercer plugs



May 8, 1951 J. BoRzl 2,551,721

GRNDING FIXTURE FOR PIERCER PLUGS Filed Jan. 27, 1950 F'IE-1.

/5 if wi a i@ /f [mem: .f4/W55 50H27,

/ @fa/726g Patented May 8, 1951 UNITED STATES rATENT OFFICE 4 Claims.

The present invention relates to a supporting fixture and more particularly to a supporting fixture suitable for holding a piercer point in proper position for grinding the back end thereof.

The piercer points normally used in modern tube mills are cast alloy steel. The purpose of grinding the back end of the piercer point is to smooth off the rough cast surface thereon and make the back end approximately normal to the long axis of the piercer point. The proper angularity of the back end relative to the long axis of the piercer point is necessary so that the piercing mill mandrel bar will fit ush against the piercer point and thus push it in a straight path during a piercing operation.

Prior to my invention, this grinding operation was performed by hand. The operator manually held the piercer point against the grinding wheel and rotated it by hand as the grinding operation proceeded. The hazardous nature of this operation is obvious. Any accidental mishandling of the piercer point while being ground on a high speed abrasive Wheel was likely to cause serious injury to the operator himself or to workers nearby. f

It is accordingly an object of my present invention to provide an adjustable supporting fixture for rotatably holding an elongated workpiece with one of its ends in contact with a rotating grinding wheel.

This and other objects will be more apparent after referring to the following specification and attached drawing, in which:

Figure 1 is a plan view;

Figure 2 is an elevational View, partly in longitudinal section; and

Figure 3 is an end View.

Referring more particularly to the drawing, reference numeral 2 indicates a rectangular shaped base plate having a center slot 4 on its under side parallel to its long axis. A plurality of elongated holes 6 are spaced in alignment along the slotted portion of the plate. The holes 6 are elongated in the ldirection parallel to the long axis of the slot. A cradle support 8 is welded or otherwise attached to the top surface of one end of the base directly over the slot. The support 8 consists of a short length of steel angle lll welded or otherwise fastened in horizontal position on the top of a vertical supporting bar l2. The angle I6 is slotted as at i4 and i6 to accommodate a pair of rollers i8 which may be small radial ball bearings mounted on axles 26 which are welded or otherwise fastened to the outside surface of the angle walls across the slots I4 and I6.

The base plate 2 may be fastened on a supporting platform 22 adjacent a grinding wheel 23 by nut and bolt means 24 as shown in Figure 2.

An end supporting element 26 cooperates with and is adjustably positioned behind and in alignment with the cradle 8 on plate 2. End support 26 consists of a cup 28 holding a ball bearing 30 of the radial-thrust type therein, an upright supporting plate 32 and an inverted S- shaped handle 34. Cup 28 is welded to one face of plate 32 while handle 34 is welded to the opposite face as best seen in Figure 2. Support 26 is detachably held in the base plate 2 by means of a hook projection 36 on the bottom of handle 34 which ts into any of the elongated holes 6. The hook 36 is iitted into the proper hole according to the length of the workpiece being processed.

In operation, a piercer point W is placed on the cradle B with its back end facing the periphery of the grinding wheel 23 and hook 36 is inserted in the appropriate hole 6. The end support 26 is then manually pushed against the grinding wheel by means of handle 34, thus engaging the nose of the piercer point in the ball bearing 3U and forcing the back end of the piercer point against the grinding Wheel. The bearing support at its front end causes the piercer point W to revolve as it is being ground, resulting in a smooth back end substantially normal to the long axis of the piercer point.

While one embodiment of my invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. A grinding fixture for supporting a piercer point or the like for the grinding of one end thereof by a rotating abrasive wheel which comprises a base plate mounted adjacent said abrasive wheel, said plate having elongated holes therein spaced apart on a line extending normal to the grinding surface of said wheel, a cradle support mounted on said plate at the end thereof adjacent said abrasive wheel in line with said elongated holes, and an end supporting cup slidably mounted in one of said elongated holes adjacent said cradle support.

2. A grinding ixture as deiined in claim 1 in which said cradle support includes a vertical supporting bar member rigidly aiflxed to said base plate, an angle member substantially V-shaped in conguration rigidly attached at its apex to the top of said supporting bar, said angle memu ber having openings in the side walls thereof, and rollers rotatably mounted in said openings.

3. A grinding xture for supporting a piercer point or the like for the grinding of one end thereof by a rotating abrasive wheel which comprises a base plate mounted adjacent said abrasive wheeL'acradle support mounted 'on said yplate at the end thereof adjacent said abrasive wheel, and an end support mounted on said base plate on the side of said cradle support remote from said grinding wheel, said end Ysupport including an upright plate member, and a cup having a radial-thrust type ball bearing therein 'rigidly attached to the surface of .said upright plate facing said cradle support.

4. A grinding fixture for supporting la piercer point or the like for the grinding of one end thereof by Ya rotating abrasive Wheel which comprises a base plate mounted adjacent said abrasive wheel, .said :plate having elongated holes therein spaced apart .on aline extending normal to the grinding surface .of 4said Wheel, a cradle support mounted on said plate at the end thereof adjacent said abrasive wheel .in line with said elongated holes, said .cradle support including a vertical supporting 'bar .member rigidly affixed to said base plate, an angle member substantially V-shaped in configuration rigidly attached at its apex to the top of said supporting bar, said angle member having openings in the side walls thereof, and rollers rotatably mounted in said openings, and an end support mounted in one of said elongated holes adjacent said cradle support, said end support including an upright plate member, and a cup having a radial-thrust type ball bearing therein rigidly attached to the surface of said upright plate facing said cradle support.

JAMES BORZI.

REFERENCES CITED The following references are of record in the `file of this --patentz UNITED STATES PATENTS Number Name Date 40,386 Williams Oct. 20, 1863 1,430,063 Diesel et al Sept. 26, 1922 1,873,067 VStromgren Aug. 23, 1932 2,054,159 Holcomb Sept. 15, 1936 2,264,179 Johnson Nov. 25, 1941 FOREIGN PATENTS Number Country Date 126,962 Great Bri-tain Dec. 18, 1919 

